drivers/char/tuner-3036.c

   1 /*
   2  * Driver for Philips SAB3036 "CITAC" tuner control chip.
   3  *
   4  * Author: Phil Blundell <philb@gnu.org>
   5  *
   6  * The SAB3036 is just about different enough from the chips that
   7  * tuner.c copes with to make it not worth the effort to crowbar
   8  * the support into that file.  So instead we have a separate driver.
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License
  12  * as published by the Free Software Foundation; either version
  13  * 2 of the License, or (at your option) any later version.
  14  */
  15
  16 #include <linux/module.h>
  17 #include <linux/kernel.h>
  18 #include <linux/sched.h>
  19 #include <linux/string.h>
  20 #include <linux/timer.h>
  21 #include <linux/delay.h>
  22 #include <linux/errno.h>
  23 #include <linux/malloc.h>
  24 #include <linux/version.h>
  25 #include <linux/init.h>
  26
  27 #include <linux/i2c.h>
  28 #include <linux/videodev.h>
  29
  30 #include "tuner.h"
  31
  32 static int debug;       /* insmod parameter */
  33 static int this_adap;
  34
  35 static struct i2c_client client_template;
  36
  37 /* Addresses to scan */
  38 static unsigned short normal_i2c[] = {I2C_CLIENT_END};
  39 static unsigned short normal_i2c_range[] = {0x60, 0x61, I2C_CLIENT_END};
  40 static unsigned short probe[2]        = { I2C_CLIENT_END, I2C_CLIENT_END };
  41 static unsigned short probe_range[2]  = { I2C_CLIENT_END, I2C_CLIENT_END };
  42 static unsigned short ignore[2]       = { I2C_CLIENT_END, I2C_CLIENT_END };
  43 static unsigned short ignore_range[2] = { I2C_CLIENT_END, I2C_CLIENT_END };
  44 static unsigned short force[2]        = { I2C_CLIENT_END, I2C_CLIENT_END };
  45
  46 static struct i2c_client_address_data addr_data = {
  47         normal_i2c, normal_i2c_range,
  48         probe, probe_range,
  49         ignore, ignore_range,
  50         force
  51 };
  52
  53 /* ---------------------------------------------------------------------- */
  54
  55 static unsigned char
  56 tuner_getstatus (struct i2c_client *c)
  57 {
  58         unsigned char byte;
  59         if (i2c_master_recv(c, &byte, 1) != 1)
  60                 printk(KERN_ERR "tuner-3036: I/O error.\n");
  61         return byte;
  62 }
  63
  64 #define TUNER_FL        0x80
  65
  66 static int
  67 tuner_islocked (struct i2c_client *c)
  68 {
  69         return (tuner_getstatus(c) & TUNER_FL);
  70 }
  71
  72 /* ---------------------------------------------------------------------- */
  73
  74 static void
  75 set_tv_freq(struct i2c_client *c, int freq)
  76 {
  77         u16 div = ((freq * 20) / 16);
  78         unsigned long give_up = jiffies + HZ;
  79         unsigned char buffer[2];
  80
  81         if (debug)
  82                 printk(KERN_DEBUG "tuner: setting frequency %dMHz, divisor %x\n", freq / 16, div);
  83
  84         /* Select high tuning current */
  85         buffer[0] = 0x29;
  86         buffer[1] = 0x3e;
  87
  88         if (i2c_master_send(c, buffer, 2) != 2)
  89                 printk("tuner: i2c i/o error 1\n");
  90
  91         buffer[0] = 0x80 | ((div>>8) & 0x7f);
  92         buffer[1] = div & 0xff;
  93
  94         if (i2c_master_send(c, buffer, 2) != 2)
  95                 printk("tuner: i2c i/o error 2\n");
  96
  97         while (!tuner_islocked(c) && time_before(jiffies, give_up))
  98                 schedule();
  99
 100         if (!tuner_islocked(c))
 101                 printk(KERN_WARNING "tuner: failed to achieve PLL lock\n");
 102
 103         /* Select low tuning current and engage AFC */
 104         buffer[0] = 0x29;
 105         buffer[1] = 0xb2;
 106
 107         if (i2c_master_send(c, buffer, 2) != 2)
 108                 printk("tuner: i2c i/o error 3\n");
 109
 110         if (debug)
 111                 printk(KERN_DEBUG "tuner: status %02x\n", tuner_getstatus(c));
 112 }
 113
 114 /* ---------------------------------------------------------------------- */
 115
 116 static int
 117 tuner_attach(struct i2c_adapter *adap, int addr,
 118              unsigned short flags, int kind)
 119 {
 120         static unsigned char buffer[] = { 0x29, 0x32, 0x2a, 0, 0x2b, 0 };
 121
 122         struct i2c_client *client;
 123
 124         if (this_adap > 0)
 125                 return -1;
 126         this_adap++;
 127
 128         client_template.adapter = adap;
 129         client_template.addr = addr;
 130
 131         client = kmalloc(sizeof(struct i2c_client), GFP_KERNEL);
 132         if (client == NULL)
 133                 return -ENOMEM;
 134         memcpy(client, &client_template, sizeof(struct i2c_client));
 135
 136         printk("tuner: SAB3036 found, status %02x\n", tuner_getstatus(client));
 137
 138         i2c_attach_client(client);
 139         MOD_INC_USE_COUNT;
 140
 141         if (i2c_master_send(client, buffer, 2) != 2)
 142                 printk("tuner: i2c i/o error 1\n");
 143         if (i2c_master_send(client, buffer+2, 2) != 2)
 144                 printk("tuner: i2c i/o error 2\n");
 145         if (i2c_master_send(client, buffer+4, 2) != 2)
 146                 printk("tuner: i2c i/o error 3\n");
 147         return 0;
 148 }
 149
 150 static int
 151 tuner_detach(struct i2c_client *c)
 152 {
 153         MOD_DEC_USE_COUNT;
 154         return 0;
 155 }
 156
 157 static int
 158 tuner_command(struct i2c_client *client, unsigned int cmd, void *arg)
 159 {
 160         int *iarg = (int*)arg;
 161
 162         switch (cmd)
 163         {
 164                 case TUNER_SET_TVFREQ:
 165                         set_tv_freq(client, *iarg);
 166                         break;
 167
 168                 default:
 169                         return -EINVAL;
 170         }
 171         return 0;
 172 }
 173
 174 static int
 175 tuner_probe(struct i2c_adapter *adap)
 176 {
 177         this_adap = 0;
 178         if (adap->id == (I2C_ALGO_BIT | I2C_HW_B_LP))
 179                 return i2c_probe(adap, &addr_data, tuner_attach);
 180         return 0;
 181 }
 182
 183 /* ----------------------------------------------------------------------- */
 184
 185 static struct i2c_driver
 186 i2c_driver_tuner =
 187 {
 188         "sab3036",              /* name       */
 189         I2C_DRIVERID_SAB3036,   /* ID         */
 190         I2C_DF_NOTIFY,
 191         tuner_probe,
 192         tuner_detach,
 193         tuner_command
 194 };
 195
 196 static struct i2c_client client_template =
 197 {
 198         "SAB3036",              /* name       */
 199         -1,
 200         0,
 201         0,
 202         NULL,
 203         &i2c_driver_tuner
 204 };
 205
 206 EXPORT_NO_SYMBOLS;
 207
 208 int __init
 209 tuner3036_init(void)
 210 {
 211         i2c_add_driver(&i2c_driver_tuner);
 212         return 0;
 213 }
 214
 215 void __exit
 216 tuner3036_exit(void)
 217 {
 218         i2c_del_driver(&i2c_driver_tuner);
 219 }
 220
 221 MODULE_DESCRIPTION("SAB3036 tuner driver");
 222 MODULE_AUTHOR("Philip Blundell <philb@gnu.org>");
 223 MODULE_PARM(debug,"i");
 224 MODULE_PARM_DESC(debug,"Enable debugging output");
 225
 226 module_init(tuner3036_init);
 227 module_exit(tuner3036_exit);